SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3336e1aaa1a19b3a3e39b7836b07c65226c3dd9c1cae790cf1136a4897703a44' 
  AND token = 'HqBXKXu7SmrUL6BTLcdsjRivHippZs1CBpdwlaskUrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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