SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f072cacb6acaea095d27cc3d4c79adbfe476e2736644aaeaba2de627f6c3b2d' 
  AND token = 'k1HklZxEkpSYSsq99aaHRRs5Ifr7JpCoUqCQ6BxIx+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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