SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bb20b74a79203589da4f685a062b78f37c57f53009975e8dc616a8a99889cd7' 
  AND token = 'MXmFtY9ieN4nqufY6L2Po1wa6oODqTMk/Obi28VQF0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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