SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2acf541567820b80b9be66ed233607b97bd997dc3cb7bd6e97214b6806da190b' 
  AND token = 'sqrExuc/jCgVwUemUW+DCjmQEu/xkYUE1Bzpt8Exgc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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