SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1db1938418597e41bce148fab800bde6872f71f9e18afae88567147bd9566d6' 
  AND token = 'HTYpuTGz9HWppvEmzCaP5NLCDkskiAqW8MN0pgohgvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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