SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0548c6f430bd5ac928fcf40fa85075be1df0c3dfcd6a7e020d2647bb5df496f' 
  AND token = 'F/lCHa7JNJ/ysAavaSqaLobNPc26AevIeoVpTMgOGeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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