SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7fcd9fc3d87848fc418880ee6bc24fb1f19f33ad685a4a53ea3f2ba3a615bba' 
  AND token = 'igSI/gY4RfGrCQpZ6vA51CjtLFLNthJfGX4N7ndGBKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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