SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1d4dfc75ab23ec89f5870c8d238876cb061f5438f791594910dfd151495a034' 
  AND token = 'ikPHosv3+d7PCPRe9ZpOnS6VNAYhboF/6QwcnaXV5jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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