SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23510edec0b6972126c11aede6696661b1adcbfdb98fe68bce81c3d2d05b8565' 
  AND token = 'tllEyaHb2ZtuZD8Yf24LKJaT9+jUPGgQXt1BlaPTRgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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