SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f7c3d05da4ab8c762133f054e9aaced5cb6cd2cf22563ad47d67221614ba124d' 
  AND token = 'KHVoCuvI6aZpjqct/YsyrYu4SLjJmtPQqHY6hgkEeR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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