SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7349db833aa1d9dd2e74b0cb0e28354ceb1df699b73c40d1a3a3fe7824bf884' 
  AND token = 'UBE0MXzL+mQP64JGQP0RZuJQ/GkXFWnjMsU7DGR5PrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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