SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd09167711a692f4dc24bdeaca1b33c1be6414ff6bb8fb332d2f50f5211c3544' 
  AND token = 'mrsdwDy9DzOr+t/1wzh1x2KXxHvZ//pPBh022YLVGuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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