SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bd1053ff336686ba8b593f048d9612d3007a85d098a31b31c37baab3e4d3e96f' 
  AND token = 'cjxFmTqEMh3x08ssVE8V3YuquPLJ1GJH7r6urbgCQ1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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