SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1021ee48d63f8f56d79a57cb7aba37cc48bc0e7927c2e07ffc45e8963b45d57' 
  AND token = 'Wouu6WXsmJbEoBJlCI0HAESLvfzVBUIJWF+LQhpzaUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}