SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56d3f3635287ee686372f8ef22c30884ce42fbf9fcf9e160c30e548a46375dd0' 
  AND token = 'lvUmtRKKT06iu9ldvkH7znXwm44hi1WF+ADhljyvWoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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