SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49cd5a366584624a13ffe68f585917b53928fa400b08e04578fbb9d091afd28b' 
  AND token = 'ghuxJReCDO154UjiGPsk+x4z3tKxuEtJvWdKgKCYJ9A=' 
  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"
    }
  }
}