SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '600531b508ade2d642b4f9fc6044706c1c9fcf7b5f946a15c58ebf23a860b3ed' 
  AND token = '9BDYcNENsbuuqQ99JAw5EnkKlXC8Zs+8b4COxxcFqFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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