SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6b7ba809883d43fafb6585399fc1264e88dfa93c86bafa7664fecf101e5568' 
  AND token = '2/BrU8NZXTQMoeuhmqvI/h5vkn8J1VYckFGy2AEJZAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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