SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07fd8f71c6c1706d452f940edbb3921993a7acf6245dcb21acfb07c2418f66a1' 
  AND token = '9F7UsgV/0byA5Y58FSAf4pll3l0MPkO+HpeebWqOIMI=' 
  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"
    }
  }
}