SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c0ee44d78da65a23aa8428d5534ef897f75ff30112a365f912f0a607582e2d' 
  AND token = 'tkTYc619k4SXjMnfQLmA0svlC0R3ne2AvyuFSddnd2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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