SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69c654a847f7e51192f70e596cc3a968dfdbc1ffbb2b0cef8cbcbe2be0762a32' 
  AND token = '6LdGWzRfdGGiGf7eErGmYKszaEoZngFDdBxnzTuHn6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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