SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '78a2953cd2b8fbac5dd7d685b9e89ca3f826f25b9fca8f4345486e7eaa1249ec' 
  AND token = 'tBM/uhl5wYLR7Pz0qB+Ue+5xumnp0XMF+8IUvmBF484=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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