SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a17a233953493454cc7ba449246c0e4970dc7efe80b241657cf670e7a345b4be' 
  AND token = 'HNDqeqoNHUEPIERHq+mA0LLPG7WowlrrMm6j32j/tFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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