SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d2871b6492533e795ffb3428fd5a5d0760bbf638594522672eb6552f2c8aff' 
  AND token = '5Imfbng5I9BsTW5rw/oXQw1gHOWO+FLNKN7PYGGvKIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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