SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e45856cfaaf10778811d600bbbaa7558db31e1be293f9a0d6cf28498ea1dbc38' 
  AND token = 'zVBpkuVdfKWq0zbvq4Z3UUY2q12/cswv/K6zk9hswq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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