SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7307a92a1a75af90b6a0a1442253203de837379f9b43c17805de453b553f0cf1' 
  AND token = 'UR5Z+o07eBUBkoDRt+bkTtYPZozowvucqDJqLnhtzmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}