SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9956ba7168ea73983efed6beaf3513916d2b4be9186ebe8946df27797bdd0387' 
  AND token = 'Kr7cFZZcSJaX2XB82iSfu+CjHkYmI5qmNljB4Ca/9ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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