SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4c64d68ea5e7b25fca0d140367ef793a3f0b60a9a2d46efb892c4d2b31a7970' 
  AND token = 'GOFwH3zynb6F7CGKCzl28VLADVean8LOUAoOrs74Fqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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