SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5337457b053faeea9656a385f4d827df8f54ef381f905d392eb15d1c6444e7fb' 
  AND token = 'T3OSpXoPR/sgk5ijJGhquOh6WwD0Gm1DYbPNsUK6jcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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