SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc4c541977eba6c2989c9bf5466abe24b23f2b369af7384d8f85023871b9a690' 
  AND token = 'unruNBOqs6DGqHF8MRrJ0g5nSQAuL03jID+ya6CvhA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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