SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29ca1337686dc8bdfb34f805a6ec2fca03b47d2c3e623061eea6f6ec5ae010b1' 
  AND token = '8vfqbzhB1/zCEOFKj5g9zcWenhWN1bDoLQLmY5iVcO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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