SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '539acaf6136d13dd3fe3b2591cdab2bb92ef817555fbdc3e2f0ca4180eb114fd' 
  AND token = 'Qovg4fCaJCI7X7leUGjYSa5yNSmcXtP3yThVhOS5Bnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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