SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04145342ea5e2a580b4c8a17f963b19daab31d60da3bcc7659751857174463d' 
  AND token = 'AC+tNwf1BHv+U1iMG2PXymPxEc9NDS9srgpTHZjvwzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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