SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea0261e15ac6a05c3e48afa9aa79af2c392a0562bf88443a953dba595aa6e6d8' 
  AND token = 'yft3ZToOGiytoDjYbGbHPI2kXouuroF93dedN8kldIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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