SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'baa4ccde6e079c5bebfa4377d5a9f9523a16d59c10d22f35803048453d6421b0' 
  AND token = 'j4TswmGJ1SOXp076GL/gLulJn3v30+zLvsivxZywNkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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