SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cee4cc1f36e10fc2c6ba9cf31f59b18ab116cb88848c11fb1442aadccb49b93c' 
  AND token = 'a/QAOSfM9qVJ3u89UgA04R0dtRB3BprJBwDvHkOVlHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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