SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7799884c49bb71d040d6dfd9d477fcce029663e20a68cf773ae9645853178fa0' 
  AND token = 'SB3sPH9SjqymfEBv9LH49zz1EcqELWpVoWOR3m7y/O8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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