SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dafcf84965b027b26fca85fd456270f3f731d1afbafa921dd74ce5fce81a5c5' 
  AND token = 'nwa5UxWDesPLQ0ll0IW1Gmm2mqdO8EhGyLf3UX4E7Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}