SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c75bce112894a8b2c25e627407f2eb533dd4a8812c3aa72e501f983e8ada5a13' 
  AND token = 'TTIRGXfHU27EqD+4FoF/KBBdfd3up7xZTZRpWGj6KlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}