SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aba4939644b2bd2801c4f666c476f951b8557290e1ed58ad9627f36c7153f743' 
  AND token = '55troAEm4M4GSoDlHWAxdtJrKK5w6q3Tt+N617nrvQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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