SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92010f141ab0750c95526b491e48c9bde9d0bf708c3a0ff890c02cf315215502' 
  AND token = 'cORSrDtmaPeBQxVVpVlGK33eYpIOnaRvvDr219B4aoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00078

JSON explain

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