SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e09003034202b9aaf2468f8ef79686d0dbd8995d8f50ae13eaabc8a039efecf1' 
  AND token = '8/HOcOwsuivAbD9KcdDbN7VLPpFb6iKCIvGVCVKlQ60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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