SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30d7d28a35043deef9cd5997ffdaf490c3a97b4ee351cce65d5fb61456f2548' 
  AND token = 'ibSaK/6ASZgh294hTu1BF+MwIigCYvFKpNq+TMWr6xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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