SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e8d603307c099ba5a2023f4d3f749de0a76879cf4d027b841f5bc7cbd852207' 
  AND token = 'Tz9Y5Z8+nBIKwEugN7AtXwcwfIP7bhZxvQgdXQdFCyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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