SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d35279696bb8832baf498aa86db01d6095646b3d405fd06d8cb4c937e0ad720' 
  AND token = '7HZ+sZZADo058iCZNCe8jhN7A2ZuiLSS9GGOCnVv1rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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