SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bb9e947fea8f8d1d97ecf6bf9d55f563219e95a10090680546187b0df2886c33' 
  AND token = 'XhtCe+5LWW9UMqJR2ahuLEt+qR+FhoMKbt4Vz3WvFWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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