SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb545c94cdffbf648e1f1595764541a03b2a0453cc49920244658bd7bbf2f97f' 
  AND token = 'pQHMi9D0Cudl9CyDZz6Avt3a0W52HAhwGQreLjlV+vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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