SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c56063c8c7398c2572b480ffec69ad71004cf6679daeea3b60249b130ea835c9' 
  AND token = 'YpEFLFBW3W5pLf76V4xrkc73uJgkaOSwfPrniPmidVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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