SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17fc38f22e5ab591c4126dd1288544199bdf26548a3f7c48c3fe70fd88513368' 
  AND token = 'E1sNgwIybR9ufYGq014JBR+erYZrFv01pAuPpCKQq/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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