SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6174580d58771f05ee233c4c61fbe1aefcc0c26cd5a61493a40f84751ff556aa' 
  AND token = '9HRJ+PYfaOMFzQC1f0J8zDctQd1h8qjMHTDbrcJ16Jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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