SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e54ce9285a4392d5fdd7225b58812ba1c273b90f028b2c57807b5327465453fb' 
  AND token = 't6H4Hq8ysfhKKY33bGjoZxbrzLMyHmlY+Q3vI/fZ4uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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