SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9084fb9ee8751a9214f6427b9f85d4cf4cf36eb6390ff20d187f42f02746e34c' 
  AND token = '9gmAmRPWQiCJShwyxgANx3pTcyOuQdVYK8FLJ+BZJAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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