SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdbc46a7fd358e881ac77a32cc364eea2a124baca28c5e68b8b882250b2a855' 
  AND token = 'kqpNtlxi+jDLKh2wtY2VX3cIcL63LVrS88nFy3P9gxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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