SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f3659d29aff16c270d5351d7871b9c4835551e53c1caea9d11bb113bf9ff419' 
  AND token = 'e7hL/Phk+cZqdQIoEjzEOEVvQcB0vv0sHsqXsydrJpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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