SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cd948653e2a1b351228b2906f81885fc6afe91602895c73d539ea1e40ac0e6e6' 
  AND token = 'Tmoz1hO4U7vzeg7l2pHA9gJEPRMqK8+EGdQFa4VtL5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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