SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d5389d263dc43269d37ca11cced4062b89339a6e386a311ec456916612cbb9' 
  AND token = 'reWqxUuvxWT5FiIBXMBdnl3ybNthXZJgNzYClw/gyt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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