SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecadc555dcf056f04583aec34a04117d58e523d9a10fa6a0567949e114cc4492' 
  AND token = 'ruMvVxp6FQ3I3/XKXnbSsixk1Pv/cS7S2crbIETkUjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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