SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eae44fb1d72378194e3a01b29acfe62b9fb354c4132a73e34e92820ebb2fec0' 
  AND token = '3YZSDytuccL+tadjfHqCzQrBzen3HbvIEp/pRjyt5j4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}