SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e7a72e29d2d6e0309dab22bf5078111633a0b374b1e7218d75bdece9b5cd100' 
  AND token = 'WyxR4fEsdw9vZOYfCHfv9Gk+NUS+4pT1W5Yaxnk2OsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}