SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a99818011b78c557009dd33c660d7a90a31348816fe77b0bd43dc6412f9c58b4' 
  AND token = 'rnLKBcD6yV+WBdc/NjIaQqbBfjQIzYjc0GqSgKaafPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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