SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f36756639d342b629c24080e47bcc75e3ed1c71b285648788c833c97584a60' 
  AND token = 'dnLs2cEK3bBorAQ0yNyTI272pKaCw7eZ0N4MuPRKWhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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