SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a47f9828c11724c035790fb0528de3a3ff0a4adb79de65a2a83776a3179d019' 
  AND token = 'OubqyWA02dKOmsFTh8XErfoe/qOjeWe7jYkMg8l2wpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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