SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5569da6c71d69ddd7e9a4983bd08fff45cf864dd395ef043182faadb0f0c6c02' 
  AND token = 'cVXaLREGmwrvByx3N/Y9pkKMfNrokXXGWEpi0rI5jFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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