SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af3facca0a44b3044668090de290b5c7b49a067f943387a3b6fb89ef2dc7c93' 
  AND token = '94OoNk28IZS2t8in9Ony7sZt4+dbBUkGgryXTySwONY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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