SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '99d6eb3910ae8080aed29715ff1d73edd62f6074c162b13661904b5dd767e0a1' 
  AND token = 'Rv9EIKX06W5C9OD2jujg2/ji1MkbpnRfVYwMExzCii8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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