SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2f8fa9b6cf59fcc855f559b11397ff78653a56e334b6328113087a978d7fd50' 
  AND token = 'cHYhITZitt+szifB4V4oEim7bRwKVq1mFwkBOUHaGHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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